Maxi Back Synchronous Chair. Sonix Choices offers a stylish range of operator seating that provides both high quality and great value. Certified by FIRA as having passed BS EN1335: (2000): Part 2 for strength, safety and stability. Quality, affordable, hardwearing fabric favoured on many lines. 100% Pyratex, 60000 rubs. Bs 7176: 1995 Direct Test for Medium Hazard premises. PYRA fabrics are suitable for use in premises categorised as Medium Hazard.. BS EN 1021 - 1&2: 1994. BS 5852 Section 4, NI5 (passes cigarette and match ignition source 5). UNI 9175/87 - Class M1 Note. Computer or at-desk tasks are part of work, typically 7-8 hours a day. Ideal for secretarial, word processing, clerical, professional and accountancy jobs. Up to 18 stone/114kg. Synchro tilt movement allows the seat and back to move together in a ratio to each other - back to seat ratio of 3:1. Users can adjust height of seat to maximise support for legs. Optional fixed arms, Height-adjustable arms and De Luxe Height-adjustable arms available. WxDxH; 520x490x470-560mm. Backrest Height: 580mm. Colour Charcoal.